Optical switchers can fulfill the same functions as all-electrical switching systems and are expected to play a key role in the near future. In this thesis an analysis if an optical system that can potentially behave as an optical switcher is discussed. This configuration consists of three microring resonators which are coupled and tangential to one another in a topology that is similar to the Leibniz packing or Apollonian gasket. The ray-transfer matrix approach is used in order to represent the whole system by a single matrix. The structure receives an initial input signal and gives an output signal, which is changed by only a scalar factor. This description is equal to an eigenvalue problem, where the matrix of the system operates over an initial vector and results a product of a scalar (the eigenvalue) times the initial vector. Due to its unique geometry each ring is divided into two unequal segments. We introduce the loss coefficients to express the attenuation along those segments. The relation between the loss coefficients is being examined and the results are verified by simulations.

Various nanostructured materials display unique and interesting optical properties. Specific nanoscale objects discussed in an experimental perspective in this dissertation include optical metamaterials, surface plasmon sensors, and two-dimensional materials. These nanoscale objects were fabricated, investigated optically, and their applications are assessed. First, one-dimensional magnetic gratings were studied, followed by their two-dimensional analog, the so-called "fishnet." Both were fabricated, characterized, and their properties, such as waveguiding modes, are examined. Interestingly, these devices can exhibit optical magnetism and even negative refraction; however, their general characterization at oblique incidence is challenging due to diffraction. Here, a new method of optical characterization of metamaterials which takes into account diffraction is presented. Next, surface plasmon resonance (SPR) was experimentally used in two schemes, for the first time, to determine the transition layer characteristics between a metal and dielectric. The physics of interfaces, namely the singularity of electric permittivity and how it can be electrically shifted, becomes clearer owing to the extreme sensitivity of SPR detection mechanisms. Finally, ultra-thin two-dimensional semiconducting materials had their radiative lifetime analyzed. Their lifetimes are tuned both by number of atomic layers and applied voltage biasing across the surface, and the changes in lifetime are suspected to be due to quenching or enhancement of non-radiative process rates.